Answer:
Because it introduces the reader to a secondary story that is totally relevant to the original story. Without this device, we would lose precious details of the story that the main narrator was unaware of.
Step-by-step explanation:
Frame device is a narrative technique that refers to the process of inserting, within an initial story, another story. Generally, the objective is to present an introductory story as a way to emphasize a second narrative or a set of short stories. The framed narrative takes readers from one first story to another, smaller (or several) within it.
The importance of this device is that it introduces the reader to a secondary story that is entirely relevant to the original story. Without this device, we would lose precious details of the story that the main narrator was unaware of.